Drafting instrument



April 131954 E. F. MATTHES 2,674,803

DRAFTING INSTRUMENT Filed June 28, 1951 IN V EN TOR. E2 M5)? FM 777/55 BY Mf M ITraRA/Eys edge ruler is denoted Patented Apr. 13, 1954 UNITED STATES PATENT OFFICE DRAFTING INSTRUMENT Elmer F. Matthes, Minneapolis, Minn.

Application June 28, 1951, Serial No. 234,036

2 Claims. 1

This invention relates to drafting instruments and particularly to drafting instruments designed to be used by draftsmen for drawing lines to be used as guides for lettering. The invention consists of an instrument having a side thereof adapted to slide along a straight-edge and having a slot therethrough at right angles to said straight-edge, said slot having a series of shelves cut therein alternately on the right and left hand sides of the slot. Each such slot is designed to accurately position 'a pencil with respect to its distance from the straight-edge while the pencil is being moved in direction toward the side of the slot containing the shelf and to allow the pencil point to slide away from the shelf and onto the next shelf in direction of the straight-edge when the direction of travel of the pencil is reversed.

Use of a drafting instrument made according to the invention will allow the draftsman to draw a series of parallel lines properly spaced for lettering as rap-idly as he can move his pencil back and forth across the drawing paper. This is a considerable improvement over any drafting instrument heretofore of commerce.

In the accompanying drawing forming a part of this specification,

Fig. 1 is a plan view of a drafting instrument made according to the invention as when resting against a straight-edge;

Fig. 2 is an enlarged sectional view, taken on line 2-2 in Fig. 1 and showing a portion of a pencil in position for scribing lines to be used as guides for lettering; and

Fig. 3 is an enlarged fragmentary plan view of a portion of the drafting instrument as in Fig. 1 with the movement of a pencil point relative to said drafting instrument indicated as a dotted line.

Referring to the drawing and the numerals of reference thereon, a drafting instrument of transparent or translucent material made according to the present invention is denoted H). A straight-edge 25 is a part of the instrument and bounds one side thereof. A :portion of a straight- A slot l2 extends through the body of the drafting instrument at a left side thereof as seen in Fig. l, and is perpendicular to the straight-edge 25. A similar slot to the right of the drafting instrument is denoted l3. Each of the slots 2 and I3 consists of a relatively wide cutaway portion I4 and a narrower cutaway portion l5. A series of shelves in the wall bounding the slot on the right as seen in Figs. 1 and 3 are denoted I6 and a series of shelves on the wall bounding the left side of the vided for by the shelves of slot I2.

slot are denoted IT. The spacing between the alternate right hand shelf l6 and left hand shelf I1 is in each case equal to the particular spacing desired between the adjacent lettering guide lines. That is, the spacing between the right hand shelf. Hi and the next left hand shelf I! in direction toward the straight-edge is equal to the spacing desired between two adjacent parallel guide lines, and the spacing between said shelf I1 and the next s'helf It in direction toward the straight-edge is equal to the space required to reach the next lower guide line. The spacing of the shelves in slot I3 is such as to provide lines for letters larger than those pro- A top surface 26 of each of the shelves l6 and I1 is inclined from adjacent the side of the slot from which the particular shelf extends slightly downwardly toward the center of the slot. The angle of each of these top surfaces 26 is such that a line extending along said surface toward the opposite side of the slot will intercept that side at a position above the top surface 26 of the next shelf down on the opposite side.

A set of three scribe marks IS in the surface of the drafting instrument ID are parallel to the straight-edge, in alinement with three adjacent left and right hand shelves and are connected by a scribe line at right angles to said straightedge. A top line of each set I8 is denoted |9, an intermediate line is denoted 20 and a bottom line in each set is denoted 2|.

As the shelves alternate from right to left, it will be seen that where one set of scribe lines I 8 has a top line I9 thereof alined with a shelf B, an intermediate line 20 will be alined with a next adjacent left hand shelf I! while a bottom line 2| will be alined with a right hand shelf Hi. The next set of scribe lines l8 will have its top line I9 alined opposite a left hand shelf its intermediate line 20 alined with a right hand shelf l6 and its bottom line 2| alined with a left hand shelf IT.

A scribe line 22 visible on the drafting instrument l0 extends parallel to the straight-edge. The distance between this scribe line 22 and the top shelf l6 and its corresponding top scribe line I9 is equal to the distance between each scribe line 20 and the next adjacent scribe line H! of the next lower set of scribe lines in direction toward said straight-edge. This is so in both the case of slot l2 and slot I3.

In operation, the straight-edge ruler constituted as part of a T-square, triangle or other similar drafting instrument is placed on the paper on which it is desired to inscribe the guide lines. The ruler is positioned so as to be parallel to the desired direction of the guide lines. The straight-edge 25 of the drafting instrument It! is brought in contact with the straight-edge ruler l i as shown in Fig. 1 and the two are then moved relative to the paper which is to be lined. The sets of scribe lines I 8 are used to help determine the desirable scale of the lettering and to give a picture of thever-tical spacing of the finished lettering on the work sheet. A sharply pointed pencil 23 is inserted against the right shelf 16 which is farthest from the straight-edge.

A slight pull is exerted on the pencil in direction 7 toward the straight-edge and the pencil is moved toward the right as seen in Fig. 1. This willcause a line to be inscribed on the jpaper beneath the drafting instrument which will be parallel to the straight-edge and will coincide with the scribe line is at the top of the drafting instrument. Whenthe line is of'sufficient length-the direc tion cfthe pencil is reversed and as the pull in the direction toward the straight-edge is maintained the pencil is moved quickly to the left. This will cause the pencil point to slide from the top surface 28 of the shelf 15 and to become engaged against the left end of the top edge 25 on the shelf I! immediately therebelow. As the pencil is moved over the paper to the left, a line will be inscribed which will be parallel to the straight-edge and will coincide with scribe line 20 of the top set of scribe lines Hi. When a line to the left of sufficient length has been drawn; the direction of the pencil will again be reversed and thepencil will slide from the shelf IT to the adjacent shelf H in direction toward the straightedge. This path of the pencil from the shelf IT to the shelf [6 and to the next adjacent shelf ll in direction toward the straight-edge is denoted by the dotted line 24. The actioncan be repeated by moving the pencilto-the right'and left as quickly as desired while maintaining slight pull indirection toward the straight-edge until the pencil has come to rest successively in all of the shelves i-B and H. This change of direction can be made with-great rapidity and consequently the guide lines can-be rapidly completed.

Should it be desired to produce more than the four orsix sets of guide lines available through the-single use of the drafting instrument, the scribe line 22 can be positioned'directly over the bottom line of the lowest set of. guide lines. in-,

scribed during a single operation ofthe device and the straight-edge ruler then brought in contact with the straight-edge 25 of the draftin instrument again. The pencil can then be Put once more against the top shelf 16 on the right of the slot and moved to the right and left until the desired number of sets of guide lines are produced.

It is obvious that a drafting instrument can be constructed within the scope of this invention which would provide for more than two different scales of guide lines. Any convenient number of vertical slots such as I2 and 13 could be provided to produce any desired spacing between'thesets of guide lines and between the individual lines of each set.

What is claimed is:

11A drafting instrument having a straightedge at a lower portion thereof and an elongated slot extending at right angles to said straightedge, and a series of vertically spaced right and left-hand shelves extending inwardly from a1- ternate sides of said slot and each having a top surface at a side of said shelf opposite said straight-edge, said top surface ofeach of said shelves being inclined from adjacent a sideof said slot to the center of said slot in direction toward said straight-edge at an angle such that a line extending along said stop surface will intercept an opposite side of said slot at position above the top surface'oi the next adjacent shelf in direction toward said straight-edge.

2. A drafting instrument having a straightedge at a lower portion thereof and an elongated slot extending at right angles to said straight-edge, and a series of verticallyspaced right and left hand'shelves-extending inwardly from alternate sides of saidslot and each having a top surface at a side of said shelf opposite said straight-edge, said top surface of each of said shelves being at an angle such that a line-extending along said top surface will intercept an opposite side of said slot at a position above the top surface of the next adjacent shelf in direction toward said straight-edge.

References Citedin the file of this patent UNrrEn STATESPATENTS Number Name Date 854,351 'I-Iight May 21, 991,693 Brown May 9, 1-911 1,131,962 Rogers Mar. 16, 1915 1,409,723 Jacob Mar. 14, 1922 

